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United States Patent |
5,131,526
|
Kaak
|
July 21, 1992
|
Conveyor for a treatment unit
Abstract
The injection-moulded links of an endless conveyor belt (4), especially
designed for moving products through a treatment unit, comprise a number
of flat link portions (8) with recesses (10) defined by pulling arms (9),
said link portions (8) having slits (12) and said recesses (10) being
adapted to receive link portions of an adjacent link so that a pivoting
pin (7) passing through the pulling arms and the slits can connect both
link portions. Preferably at least one semi-circular end wall of the slits
of the uttermost link portions is at an angle that corresponds to the
curvature radius of the drums of the conveyor wherein the conveyor belt is
to be mounted.
Inventors:
|
Kaak; Stephanus W. (Varsseveldseweg 20A, 7061 GA Terborg, NL)
|
Appl. No.:
|
610857 |
Filed:
|
November 7, 1990 |
Current U.S. Class: |
198/778; 198/852 |
Intern'l Class: |
B65G 021/18 |
Field of Search: |
198/778,831,851,852,853
|
References Cited
U.S. Patent Documents
3666083 | May., 1972 | Smith | 198/778.
|
4184588 | Jan., 1980 | Lapeyre | 198/778.
|
4222483 | Sep., 1980 | Wootton et al. | 198/831.
|
4448301 | May., 1984 | Alger | 198/778.
|
4865183 | Sep., 1989 | Hodlewsky et al. | 198/853.
|
4953693 | Sep., 1990 | Draebel | 198/853.
|
4972942 | Nov., 1990 | Faulkner | 198/853.
|
5031757 | Jul., 1991 | Draebel et al. | 198/852.
|
Primary Examiner: Valenza; Joseph E.
Attorney, Agent or Firm: Zarley, McKee, Thomte, Voorhees, & Sease
Claims
I claim:
1. A conveyor, comprising an endless conveyor belt provided with pivoting
pins, for moving products along a path through a treatment unit, said unit
substantially comprising at least two drums or similar guiding means
rotatable about a vertical center line, along which said path follows a
curve of a definite grade value in a slightly tilted plane, and support
members for the remaining, also slightly tilted, track portions, the
arrangement being so that the products to be treated can be supplied at
the one drum in a low position and discharged at the other drum in a high
position or vice versa, said conveyor belt returning from the high
position to the low position via a vertical and a horizontal path portion,
and driving and tensioning means for the conveyor belt, said conveyor belt
comprising links consisting of a material that can be rolled or obtained
by injection moulding of a synthetic material, each link comprising a
number of flat link portions with recesses defined by pulling arms, said
pivoting pins being tightly secured to the pulling arms and being able to
move in the plane of the conveyor belt through slits of the link portions
disposed in the recesses, and a driving means comprising at least one
drive wheel resembling a sprocket wheel with teeth which are received in
the space between two link portions, the adjacent pulling arms of two
neighboring link portions being connected by a sleeve which can receive a
pivoting pin, at least one end of each pivoting pin being secured in an
exterior sleeve connected to an outer pulling arm, and at least one
semi-circular end wall of the slits of the uttermost link portions being
at an angle that corresponds to the curvature radius of the drums.
2. A conveyor, comprising an endless conveyor belt provided with pivoting
pins, for moving products along a path through a treatment unit, said unit
substantially comprising at least two drums or similar guiding means being
rotatable about a vertical center line, along which said path follows a
curve of a definite grade value in a slightly tilted plane, and support
members for the remaining, also slightly tilted, tract portions, the
arrangement being so that the products to be treated can be supplied at
the one drum in a low position and discharged at the other drum in a high
position or vice versa, said conveyor belt returning from the high
position to the low position via a vertical and a horizontal path portion,
and driving and tensioning means for the conveyor belt, said conveyor belt
comprising links consisting of a material that can be rolled or obtained
by injection moulding of a synthetic material, each link comprising a
number of flat link portions with recesses defined by pulling arms, said
pivoting being tightly secured to the pulling arms and being able to move
in the plane of the conveyor belt through slits of the link portions
disposed in the recesses, and a driving means comprising at least one
drive wheel resembling a sprocket wheel with teeth which are received in
the space between two link portions, the adjacent pulling arms of two
neighboring link portions being connected by a sleeve which can receive a
pivoting pin, at least one end of each pivoting pin being secured in an
exterior sleeve connected to an outer pulling arm, at least one
semi-circular end wall of the slits of the uttermost link portions being
at an angle that corresponds to the curvature radius of the drums, and the
exterior sleeves being connected through bends to the connecting point of
a link portion and an outer pulling arm.
3. The conveyor according to claim 2 wherein a longitudinal wall facing
away from the exterior sleeve abuts the opposite exterior sleeve in an
interior curve.
4. A conveyor, comprising an endless conveyor belt provided with pivoting
pins, for moving products along a path through a treatment unit, said unit
substantially comprising at least two drums or similar guiding means being
rotatable about a vertical center line, along which said path follows a
curve of a definite grade value in a slightly tilted plane, and support
members for the remaining, also slightly tilted, tract portions, the
arrangement being so that the products to be treated can be supplied at
the one drum in a low position and discharged at the other drum in a high
position or vice versa, said conveyor belt returning from the high
position to the low position via a vertical and a horizontal path portion,
and driving and tensioning means for the conveyor belt, said conveyor belt
comprising links consisting of a material that can be rolled or obtained
by injection moulding of a synthetic material, each link comprising a
number of flat link portions with recesses defined by pulling arms, said
pivoting pins being tightly secured to the pulling arms and being able to
move in the plane of the conveyor belt through slits of the link portions
disposed in the recesses, and a driving means comprising at least one
drive wheel resembling a sprocket wheel with teeth which are received in
the space between two link portions, the adjacent pulling arms of two
neighboring link portions being connected by a sleeve which can receive a
pivoting pin, at least one end of each pivoting pin being secured in an
exterior sleeve connected to an outer pulling arm, at least one
semi-circular end wall of the slits of the uttermost link portions being
at an angle that corresponds to the curvature radius to the drums, said
exterior sleeves being connected through bends to the connecting point of
a link portion and an outer pulling arm, a longitudinal wall facing away
from the exterior sleeve abutting the opposite exterior sleeve in an
interior curve, and said link portions comprising grooves at their
bottoms, the bottom side of the grooves extending in the direction of
travel of the conveyor belt, the link portions having a depth of more than
half the thickness of the link portions, and a length extending up to or
near the edge of the link portions which faces away from the pulling arms.
5. A conveyor, comprising an endless belt provided with pivoting pins, for
moving products along a path through a treatment unit, said unit
substantially comprising at least two drums or similar guiding means being
rotatable about a vertical center line, along which said path follows a
curve of a definite grade value in a slightly tilted plane, and support
members for the remaining, also slightly tilted, track portions, the
arrangement being so that the products to be treated can be supplied at
the one drum in a low position and discharged at the other drum in a high
position or vice versa, said conveyor belt returning from the high
position to the low position via a vertical and a horizontal path portion,
and driving and tensioning means for the conveyor belt, said conveyor belt
comprising links consisting of a material that can be rolled or obtained
by injection moulding of a synthetic material, each link comprising a
number of flat link portions with recesses defined by pulling arms, said
pivoting pins being tightly secured to the pulling arms and being able to
move in the plane of the conveyor belt through slits of the link portions
disposed in the recesses, and a driving means comprising at least one
drive wheel resembling a sprocket wheel with teeth which are received in
the space between two link portions, the adjacent pulling arms of two
neighboring link portions being connected by a sleeve which can receive a
pivoting pin, at least one end of each pivoting pin being secured in an
exterior sleeve connected to an outer pulling arm, at least one
semi-circular end wall of the slits of the uttermost link portions being
at an angle that corresponds to the curvature radius of the drums, said
driving and tensioning means comprising two wheels that resemble sprocket
wheels and which have a center-to-center distance which is equal to or a
multiple of the pitch of the pivoting pins of a tensioned conveyor belt in
a straight path portion, said conveyor belt being guided around said two
wheels, so as to pass at least one spring loaded tensioning roll, at least
one small roll that projects slightly above the top surface of the
conveyor belt being provided between the two wheels in order to position
products precisely perpendicularly to the direction of travel of the
conveyor belt again if they have gone off course.
6. Conveyor according to claim 5, wherein the wheels have at least two
chain crowns.
7. Conveyor according to claim 5 or 6, wherein said driving and tensioning
means comprise a motor, said motor having transfer means branched
therefrom, said small rolls being driven in the same direction via the
transfer means by the motor that drives the driving wheel.
Description
The invention relates to a conveyor, comprising an endless conveyor belt
provided with pivoting pins, for moving products along a path through a
treatment unit, said unit substantially comprising at least two drums or
similar guiding means being rotatable about a vertical centre line, along
which said path follows a curve of a definite grade value in a slightly
tilted plane, and support members for the remaining, also slightly tilted,
track portions, the arrangement being so that the products to be treated
can be supplied at the one drum in a low position and discharged at the
other drum in a high position or vice versa, said conveyor belt returning
from the high position to the low position via a vertical and a horizontal
path portion, and driving and tensioning means for the conveyor belt.
Known units of the type as referred to above, which are i.a. known as
cooling towers for bakery products, employ metal strip conveyor belts
which are mounted on conveyor chains. Apart from the additional expenses
on account of the manufacture, assembly and maintenance of these chains,
they also produce a lot of noise and they are difficult to clean, which is
a considerable drawback. During operation of the conveyor small metal
particles will be released, as is the case in other units or machinery
involving metal parts which move with respect to one another, which
particles are deposited on the metal strips and pivoting pins together
with crumbs and fat particles originating from the conveyed products.
The inventions aims to improve this situation. According to the invention
this has been attained in that a link of the conveyor belt consisting of a
material that can either be rolled or injection-moulded, comprises a
number of flat link portions with recesses defined by pulling arms, in
that the pivoting pins are tightly secured to the pulling arms and are
able to move in the plane of the conveyor belt through slits of the link
portions disposed in the recesses, and in that a driving means comprises
at least one drive wheel resembling a sprocket wheel with teeth which are
received in the space between two link portions.
It is preferred to manufacture the links by the known method of injection
moulding of a suitable synthetic material.
The adjacent pulling arms of two neighbouring link portions may be
connected by a sleeve which can receive a pivoting pin, and at least one
end of each pivoting pin is secured in an exterior sleeve connected to an
outer pulling arm. This manner of arranging the link shaft provides
sufficient space for the operation of a drive wheel, and apart from that
the pivoting pin cannot release itself under the influence of vibration.
The measures to be discussed hereinafter are particularly relevant to the
curved path portions of the endless conveyor belt. At least one
semi-circular end wall of the slits of the uttermost link portions is at
an angle that corresponds to the curvature radius of the drums. The
exterior sleeves are connected through bends to the connecting point of a
link portion and an outer pulling arm. The longitudinal wall facing away
from the exterior sleeve abuts the opposite exterior sleeve in an interior
curve.
The link portions preferably comprise grooves at the bottom, extending in
the direction of travel of the conveyor belt, which grooves have a depth
of more than half the thickness of the link portions, and a lenght
extending up to or near the edge of the link portions which faces away
from the pulling arms. This is important with respect to maintaining the
conveyor belt and keeping it clean.
If a driving and tensioning means comprises two wheels resembling chain
wheels with a centre distance equal to or a multiple of the pitch of the
pivoting pins of a tensioned conveyor belt in a straight path portion,
said conveyor belt being guided about said two wheels in such a way that
it passes a tensioning roll loaded by at least one spring, according to
the invention at least one small roll is arranged between said two wheels,
which small roll projects somewhat above the top surface of the conveyor
belt so as to position those products that have gone off course again
correctly perpendicularly to the direction of travel of the conveyor belt.
These driven small rolls again make the machine easy to clean.
The invention will be elucidated hereinafter on the basis of the drawing,
in which by means of an example an embodiment of a unit according to the
invention is represented. In the drawing:
FIG. 1 shows a top view of the left portion of the treatment unit;
FIG. 2 shows a top view of the right portion of the treatment unit,
FIG. 3 shows a longitudinal view of FIG. 2,
FIG. 4 shows, on a larger scale, a top view of a portion of a conveyor belt
of the unit of the FIGS. 1-3,
FIG. 5 shows, at about real size, a horizontal cross-section through an
outer link portion,
FIG. 6 shows, at about real size, a vertical cross-section through a link
of the conveyor belt of FIG. 4,
FIG. 7 shows a bottom view of FIG. 6,
FIG. 8 shows a longitudinal view of a chain crown for a driving or turning
wheel,
FIG. 9 show, at a larger scale than in FIGS. 1-3, a schematic top view of a
driving and tensioning means, and
FIG. 10 shows a longitudinal view of FIG. 9.
The unit represented in FIGS. 1-3 has two freely rotatable drums 1 and 2
with a diameter of 1.6 m of which the vertical centre lines 3 are spaced
apart at at least 40 m. A conveyor belt 4 (FIG. 4) with a length of
approx. 600 m. extends through said unit.
The products are supplied to the unit at drum 1 in a low position A. The
conveyor belt 4 and the products possibly positioned thereon are then
conveyed, while steadily rising, through a lowermost path portion B at the
front of the unit, subsequently around the drum 2, and then obliquely
through a lowermost path portion C at the rear of the unit so as to arrive
at the second floor or level. In this way, the following floors or levels
are also passed, in order to finally arrive at the high discharge position
D of drum 2. A roll 5 is mounted at position D so as to guide the conveyor
belt 4 to a vertical path portion E. At a level below the lowermost path
portion B, a subsequent roll 6 is disposed perpendicularly below the roll
5, for guiding the conveyor belt 4 to a path portion F which ends at
position A and connects there by means of a roll (not shown) to the
lowermost path portion B so as to make the conveyor belt 4 endless.
The manner in which the conveyor belt 4 is supported in the various path
portions is not relevant to the invention. The unit may also comprise more
than two drums or similar guidings and the path of the conveyor belt may
also comprise S-shaped track portions. However, the manner in which the
conveyor belt itself is devised is essential to the invention and
therefore it will be elucidated on the basis of FIGS. 4-7.
FIG. 4 shows five links of a conveyor belt 4 comprising pivoting pins 7, in
the position in which the central pivoting pin 7 intersects the vertical
centre line 3 of the drum 1 in FIG. 1. The three links on the left of FIG.
4 are therefore arranged in a curve along the drum 1 and the two links on
the right are so to speak incorporated in an obliquely rising path portion
C.
In the represented embodiment, a link consists of six link portions 8 which
each comprise two buckled pulling arms 9. Two pulling arms 9 of one link
portion 8 define a recess 10 which is wide enough to receive a link
portion of an adjacent link with clearance. Therefore the distance between
said two pulling arms is slightly greater than the width of a link portion
8. For the sake of strength, the pulling arms 9 of one link portion 8 are
connected by a rib 11, connecting the two buckling points of the pulling
arms 9 of one link portion 8. Without this provision, the pulling arms
might bend and eventually break. Said rib 11 is positioned so close to the
link portion 8, that the link portions, comprising a slit 12 for receiving
the pivoting pin 7, can sufficiently more back and forth in said recess.
As the semi-circular end walls of the slits 12 of the four interior link
portions 8 are simply perpendicular to the side walls of the said link
portions and therefore parallel to the centre lines of the pivoting pins 7
in the straight path portions, the pulling forces in the straight track
portions of the conveyor belt are substantially transferred to the
pivoting pins 7 by said four link portions 8. The semi-circular end walls
of the slits 12 of at least one of the exterior link portions 8 are not
perpendicular to the side walls, but they have centre lines which are at
such an angle to the centre lines of the pivoting pins 7 that these centre
lines intersect at a point which at given times substantially coincides
with the vertical centre lines 3 of the drums 1 and 2. This is indicated
in FIG. 5 by angle .alpha.. The consequence of this detail is that the
pulling force is in the 180.degree. curve portions of the conveyor belt
about the drums 1 and 2 is substantially transferred to the uppermost link
portion 8 and the pivoting pin 7, both in FIG. 7.
Two adjacent pulling arms 9 of the two neighbouring link portions 8 are
connected by a sleeve 13 in which a pivoting pin 7 can be received. The
ends of a pivoting pin 7 are fixed into bores of outer sleeves 15 by means
of a screw or pin 14, which sleeves are connected via bends 16 to the
connecting point of a link portion 8 and an outer pulling arm 9. These
bends can either be massive or comprise a hole 17, as shown. This does not
only save material, but it also provides a better (cooling) air
circulation. The longitudinal wall facing away from the outer sleeve 15 of
the bend 16 is positioned so, that it will face the oppositely disposed
outer sleeve 15 in the inner curve (left bottom side of FIG. 4). In this
way pressing forces are compensated, so that the conveyor belt cannot
"break out".
Connecting two neighbouring link portions 8 by a sleeve 13 has the
advantage that the length of the space 18 between the link portions 8,
engaging drive wheels 20 driven by motors 37 and resembling chain wheels
of a driving and tensioning means 21, can be chosen wider.
So as to be able to also use the conveyor belt in oppositely rotating units
with e.g. S-curves, it is devised symmetrical, i.e. with semi-circular end
walls in either outer link part 8 at an angle .alpha. and also having a
bend 16 on either end.
Grooves 19 are made in the bottom of the link portions 8. It appears from
FIGS. 6 and 7 that those grooves 19 have such dimensions that they are
connected to a slit 12. Therefore they have a depth of more than half the
thickness of the link portion 8 and such a length that the semi-circular
side walls of the slits are interrupted, resulting in the set of three
visible planes 22 represented in FIG. 7. Consequently, the pivoting pins 7
have to remove combinations of crumbs and fat particles deposited thereon
only over a shorter path.
A further elucidation to the driving and tensioning means 21 will be given
on the basis of FIGS. 8-10. Such a means 21 is merely represented in FIG.
3 in the lowermost path portion B, but it is standard procedure to also
provide the superposed path portions B and also the path portions C of the
unit with such a means.
Each driving and tensioning means 21 comprises a motor 37 that rotatably
drives a shaft 23. Five chain crowns 24, together forming a drive wheel
20, are mounted on said shaft 23. According to FIG. 8 such a chain crown
24 comprises a set of eight cavities 25 of which the pitch corresponds to
the centre distance of the pivoting pins 7 in a straight path of the
conveyor belt, so that blunt teeth 26 disposed between the cavities 25 are
able to engage in the spaces 18 of the conveyor belt 4 so as to drive it.
A turning wheel 27 with the same exterior as the drive wheel 20 is freely
rotatably mounted on a second shaft 28. Further guide means 29 are
provided so as to have the conveyor belt 4 follow two horizontal loops,
and a tensioning roll 30 which is borne on a shaft 31 which can be slid
far into a slit 32 of the frame and which is tensioned by springs 33. The
special characteristic of the tensioning and driving means 21 is that a
number of small rolls 34 is disposed between the wheels 20 and 27 which
project slightly above the path in order to position the products which
have gone off course, such as loaves of bread, again correctly
perpendicularly to the direction of travel of the conveyor belt 4. The
most favourable position for treatment could be disrupted during the
motion of the breads through curves about the vertical drums 1 and 2. The
small rolls 34 have such a centre distance that they clean one another
even if the smallest bit of dirt adheres to one of them, which is even
enhanced by the fact that they are all driven in the same direction by
transfer means 35 branched from the motor 37. The number of small rolls 34
has obviously also been chosen so, that the products to be treated cannot
tilt. Crumbs and the like are collected in a tray 36 which can be emptied
on a regular basis.
Within the framework of the claims other embodiments than merely the ones
represented in the drawing are also possible, particularly units having
more than two drums in which the path can include S-shaped track portions.
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